1. Field of the Invention
The present invention relates to a computer card (hereafter referred to as PC card) to be inserted into an electronic apparatus such as a personal computer, in order to add a variety of functions performed through electric connection, and more specifically a PC card having an extended portion externally extended from the electronic apparatus when the PC card is inserted.
2. Description of the Related Art
FIGS. 1A, 1B show exploded views of an example of the conventional PC card. In FIGS. 1A, 1B, the exploded views depict one face and the other face of the PC card, respectively. A main portion of the PC card is constituted of portions, which are referred to as a frame body 1 and an extended portion 2 extended from frame body 1.
In FIGS. 1A, 1B, a circuit board having circuit components accommodated in frame body 1 and extended portion 2 is not shown. On the circuit board, a connector is disposed on the right-hand side in the figure, for electrically connecting to the electronic apparatus when the card is inserted into the electronic apparatus.
Extended portion 2 is further structured of a lid 3 to be covered therewith. FIGS. 2A, 2B and 2C show diagrams for explaining the combined extended portion 2 with lid 3. Both extended portion 2 and lid 3 are formed of synthetic resin. As an example of the conventional structure, the combination of lid 3 with extended portion 2 is structured as shown in FIGS. 2A, 2B and 2C.
FIG. 2A is a plan view of a conventional PC card 10 of completed assembly, including main portion 1 and extended portion 2. Extended portion 2 is covered with lid 3, while main portion 1 is covered with a decorative panel 4. The card is inserted to the electronic apparatus from the side opposite to extended portion 2. Electric connection is made through connector pins provided at an end portion 11. The connector pins are connected to the connector of the electronic apparatus.
FIG. 2B shows assembly procedure steps for assembling extended portion 2, which are illustrated by the cross section along an X—X line, respectively. FIG. 2C shows partial enlarged views each corresponding to each procedure step shown in FIG. 2B.
Namely, in FIGS. 2A, 2B, 2C, the card has a structure such that lid 3 covers extended portion 2, as shown in the procedure step (a). Extended portion 2 and lid 3 are formed of synthetic resin, respectively having locking pieces 2-1, 3-1 of hook shape disposed on the opposite side walls. Locking piece 2-1 disposed on extended portion 2 has a hook of which hollow faces outward, while locking piece 3-1 has a hook of which hollow faces inward.
Further, the above-mentioned locking piece 3-1 has a thinner wall to the extent that locking piece 3-1 is deformed more easily than locking piece 2-1. Therefore, when lid 3 is depressed onto extended portion 2, locking piece 3-1 is deformed outward at the time locking piece 3-1 is hit to locking piece 2-1, as shown in (b), (c) of FIG. 2C. When lid 3 is further depressed, the top of the hook of the locking piece 3-1 falls in the hollow of the hook of locking piece 2-1, by which the shape of locking piece 2-1 is restored. With this, the hook of the locking piece 2-1 is engaged with the hook of locking piece 3-1, which forms a locked state. By lid 3 secured to extended portion 2, the internal circuits are protected.
Therefore, in the conventional configuration shown in FIGS. 1 and 2A to 2C, deformation of lid 3 is inevitably produced when lid 3 is integrated with extended portion 2. Moreover, when handling PC card 10, stresses such as twisting and bending are applied with considerable possibility. Undesirably, this may cause lid 3 to be detached from extended portion 2 with large possibility.
Further, since both locking piece 2-1 of extended portion 2 and locking piece 3-1 of lid 3 are of hook shape, the metal molds for resin molding are of complicated structure. This is disadvantageous to the manufacturing cost.
Meanwhile, commonly to the above points, a variety of PC cards particularly having a feature on the structure of the extended portion have been proposed. For example, methods are disclosed in the official gazette of the Japanese Unexamined Patent Publication No. 2003-91706, and No. Hei-11-99779.
In the PC card described in the above Publication No. 2003-91706, fixation of the lid into the extended portion of a synthetic resin case constituting the case of the PC card is actualized with a non-openable fit-and-fixed structure of a locking mechanism having a hook in the longitudinal direction of the PC card. In this case also, the resin molding of the extended portion and the lid is inevitably complicated.
Also, according to the above Publication No. Hei-11-99779, the PC card has a structure such that the lid to cover the extended portion is pressed by an end portion of a decorative panel, when the decorative panel is fit to the main portion with a screw.